This invention relates to a winding apparatus, and more particularly to a braiding machine of the type having a frame, a pay-out reel for a braid core, means for holding the braid-core pay-out reel, two rotary supports rotating about axes determined relative to the frame, and reel-holders for braid elements mounted on each of the supports and each bearing a pay-out reel for a braid element unwinding from the reel, the whole disposed in such a way that the braid elements coming from the reels mounted on each support and the supports together delimit two closed volumes which interpenetrate one another and comprise a common portion, the holding means holding the braid-core pay-out reel in a certain position within that common portion.
In braiding machines of conventional design, one of the two conical nappes described by the braid elements coming from each of the two groups of reel-holders has as a directrix a circle centered on the braiding axis, whereas the other nappe--owing to the periodic actuation of a set of radially moving levers--has as a directrix a closed curve which is likewise centered on the braiding axis, but which has a lobate shape. These machines are complicated and noisy. Furthermore, the speed of the reel-holders on their supports along their orbits is limited.
It has already been sought to remedy these drawbacks, and to this end, U.K. Patent No. 1,299,611 describes a braider arrangement in which the reel-holders provided for the braid elements describe different closed curves, generally circles, being guided on runways which intersect and are equipped with propulsion means. This arrangement avoids the lobate curve shape and the effects of inertia resulting therefrom; but the driving of carriages along runways creates design complications which preclude the stability desirable in designs of this type.
According to one prior art proposal (U.K. Patent No. 853,454), the reel-holders for the braid elements are divided between two rotary supports disposed so that the surfaces described by the braid elements coming from the reels mounted on each support, together with the respective support, bound two interpenetrating closed volumes. A reel for paying out the core of the braid is accommodated in the space thus defined, which is common to both volumes.
While this arrangement is topologically favorable, this prior art patent does not suggest any mechanically reliable solution for holding the reel for paying out the core of the braid. The support of this reel is held in place by the joint action of the two supports on which the reel-holders for the braid elements are mounted, so that it is subject to the effects of friction and of inertia. Moreover, construction is greatly complicated if there are more than two reels for braid elements.